In recent decades, there have been various concepts for magnetically supporting vehicles or objects for movement along a track or other conveying device from one location to another. A search of the U.S. Patent literature has disclosed a number of these, described in the following patents:
U.S. Pat. No. 5,165,347 (Wagner) shows a "Vehicle Levitation and Guidance System" particularly adapted for small scale models of vehicles, such as trains, cars, etc. There are magnetic strips attached to the bottom of the train and magnets in the track, to create opposing magnetic fields that lift the train above the track. To guide the train, there are provided center pins 36 that extend downwardly into a center channel formed in the tracks. The pins apparently physically engage the sidewalls of the channel to keep the train properly aligned.
U.S. Pat. No. 4,805,761 (Totsch) shows a magnetic conveyor system to transport integrated circuits in a clean-controlled environment. There is a stationary bed or rail having two sets of longitudinally aligned laterally spaced magnets on opposite sides at the bottom of the bed to provide support, and two Teflon guides acting against Teflon runners on the side walls to provide lateral positioning. Then the conveying platform has two similar side strips of magnets that provide the lifting force. There is a magnetic drive piston which is positioned for movement along a center tube 28. This interacts with center magnets 52 that are mounted on the platform so that when there is movement of the drive magnet (called a "piston"), the tray is caused to move along the rail.
U.S. Pat. No. 3,951,074 (Cooper) shows a system of suspending a "high speed terrestrial vehicle" that is suspended by magnets. The magnets are provided in the vehicle so that there are two sets of alternatively positioned north and south magnets longitudinally aligned on the lower part of the vehicle. Each set of magnets along opposite sides of the vehicle is positioned in a related U shaped track 13 made of a continuous nonferromagnetic electrically conductive material, so that as the vehicle is propelled, such as by jet engines, and reaches a high speed, eddy currents are induced in the track by the moving magnetic fields. The eddy currents set up magnetic fields which are directly opposite and which repel the magnets 15 in the vehicle. This provides the lift.
U.S. Pat. No. 3,834,317 (Miericke) shows a "magnetic moving vehicle suspension", and as can be seen in FIG. 1, there are in the track four magnetic loops which appear to generate opposing magnetic fields. Then the vehicle itself that is to travel so as to be suspended magnetically has two horizontal laterally spaced plates 16 and 17 (which are electrically conductive but nonferromagnetic), and also a vertically aligned longitudinal center plate 18 which is also of electrically nonferromagnetic material. Additional magnetic loops are provided at upper plate locations at 26 and 28, if these are needed. It would appear that eddy currents are formed in the plates 16, 17, 18 and 26-28 when there is relative movement between the vehicle and the track.
U.S. Pat. Nos. 3,903,809 and 3,780,667 are also patents to Miericke, and these show magnetic suspension systems rather similar to that discussed above relative to U.S. Pat. No. 3,834,317.
U.S. Pat. No. 3,899,979 (Godsey, Jr.) shows a magnetic suspension system for trains and the like, where there are permanent magnets and also electro magnets. Energization of the electro magnets is used mainly to provide an extra boost to keep the air gap clearance substantially constant in accordance with varying gravitational loads on the vehicle.
U.S. Pat. No. 3,158,765 (Polgreen) shows a magnetic support transportation system where poles of like polarity are laced one above the other to provide support.